1. Field of the Invention
The present invention relates generally to a stump cutting apparatus and more specifically to a stump cutting tool used with a stump cutting apparatus.
2. Description of Related Art
Stump cutters or stump cutting machines are generally known in the art and are used to cut or grind stumps. A typical stump cutter includes a plurality of cutting tools mounted to a rotatable cutting wheel or drum. Placing the wheel or drum against a stump and rotating it causes the cutting tools, and more particularly individual cutting teeth, to engage and cut away the stump. Tool holders, sometimes referred to as pockets, are used to secure the cutting teeth to the cutting wheel.
Since the cutting teeth operate in a harsh environment, replacement of the cutting teeth is almost a continuous job. For example, contact with the ground surface rapidly dulls the cutting edge of each cutting tooth. Further, if a cutting tooth strikes something hard such as a stone or rock the cutting tooth or an edge thereof may break or chip requiring replacement of the cutting tooth. In addition, depending upon the particular cutting tooth design or style the cutting tooth often includes a carbide cutting bit. Many cutting tooth configurations use only a portion of the carbide cutting bit, that is only a portion of the cutting bit or cutting bit edge actually performs the cutting or stump grinding operation. Such cutting teeth waste the remaining or unused portion of the carbide cutting bit. Since it is difficult and costly to replace only the carbide cutting bit, the entire cutting tooth must be replaced thereby increasing the overall costs. Finally, continuous loading of the cutting tooth can cause cutting tooth failure including twisting or bending of the shank portion. In some instances, the tooth itself may break thus necessitating replacement.
As cutting tooth replacement is costly both in material replacement costs and man-hours to remove and install each individual new cutting tooth it is desirable to use as much of the cutting bit as possible and replace only the worn, used or damaged cutting bit as necessary while maximizing use of the entire cutting bit. Further, the less material that needs to be replaced, the less the cost of replacement.
U.S. Pat. No. 6,382,277 discloses one type of cutting tooth and tool holder/pocket assembly, the disclosure of which is hereby incorporated by reference. As set forth therein, the '277 patent discloses a stump cutting apparatus including a cutting wheel and a plurality of cutting assemblies mounted on the cutting wheel. The cutting assemblies include first and second pockets, a pair of cutting teeth and a pair of fasteners. Each cutting tooth includes a shank with an enlarged head located on one end of the shank. A cutting bit formed of a hard material is located in a seat formed on the enlarged head and brazed in place. As set forth in the '277 patent, the cutting teeth pass perpendicularly through the cutting wheel and extend a distance from the respective sides of the wheel, whereby the teeth are used to attach the pockets to the wheel without using separate fasteners.
As known in the industry, it is advantageous to use as much of the cutting edge of the cutting bit as possible. U.S. Pat. No. 5,743,314, the disclosure of which is hereby incorporated by reference, discloses an indexable stump cutting tooth that enables rotation of the cutting tooth to expose a new or unused portion of the cutting edge of the cutting bit. Further, once the cutting edges of the cutting bit are used, the cutting tooth can be replaced without having to remove or replace the mounting block or pocket.
Since cutting tooth replacement is costly, it is advantageous to use as much of the cutting bit as possible in order to reduce the overall cost, including the manufacturing and fabrication cost of the cutting tooth itself. Accordingly, there is need in the art for a cutting tooth that maximizes use of the cutting bit while also reducing the amount of material and structure that must be replaced when replacing the cutting bit.